Various methods for preparing flame retardant polyorganosiloxane foams are described in the prior art. Modic in U.S. Pat. No. 3,425,967 teaches the use of mixtures containing asbestos and fibrous potassium titanate as flame retarding additives for polyorganosiloxane foams. Lee et. al in U.S. Pat. No. 4,026,842 and Smith in U.S. Pat. No. 3,923,705 teach use of platinum or a platinum compound to improve flame retardancy of polyorganosiloxane foams prepared by reacting organohydrogen siloxanes and siloxanes containing silicon-bonded hydroxyl groups. Smith teaches that flame retardancy can be further improved by carbon black. Harper et al. in U.S. Pat. No. 4,433,069 teach fire resistant polysiloxane foams having a combination of at least 0.1% each of a nonmetallic fibrous heat resistant material, at least one finely divided nonmetallic cellular heat resistant material, and at least 5 ppm platinum. The fibrous heat resistant materials include naturally occurring materials, such as asbestos, and man-made fibers and whiskers formed from glass, carbon, alumina, inorganic silicates such as aluminum silicate and mixtures of aluminum silicate with alkali metal and/or alkaline earth metal silicates. Preferred fibrous heat resistant materials are glass and carbon.
In U.S. Pat. No. 4,590,222, Bauman teaches a silicone foam composition containing a polydiorganosiloxane, a resinous copolymer, a platinum catalyst, an organohydrogensiloxane, a hydroxyl-endblocked polydiorganosiloxane, a filler and an organic alcohol. In U.S. Pat. No. 4,871,781 Weise teaches a foamable composition comprising a polyorganosiloxane, a polyorganohydrogensiloxane, a platinum catalyst, and a saturated polyhydric alcohol. In U.S. Pat. No. 5,358,975, Anderson teaches a foamable composition comprising a polyorganosiloxane, an organohydrogensiloxane, a platinum catalyst, an .alpha.,w-diol, and a resinous copolymer.